A friend has this adapter. It worked OK with his 2011 MBA after doing an upgrade to ML. I haven't tried it on my 2012 with ML. Your mileage may vary. I'm not sure if it will always work with ML, or if the existing driver from his Lion install carried over when the upgrade was done.

I got the 29 dollar gigabit thunderbolt adapter and the performance is really good (i've gotten over 750MB/s from a crossover to my older macbook pro w/ an upgraded ssd), so i don't know how good a speed you will get via a usb2 device (not better than 480Mb/s or 60MB/s since that's the usb2 spec limits).. unless that adapter is actually usb3.0.. something to consider, but i may be getting that same adapter because i am going to soon have a need for both my retina macbook's thunderbolt ports..

bottom line, if you can spare the thunderbolt port, don't mind the higher price, you'll get your money's worth on performance.. if you don't see a need of that performance (or have other external limitations like a 100meg only network), you can save some $ by getting a cheaper usb adapter

I got the 29 dollar gigabit thunderbolt adapter and the performance is really good (i've gotten over 750MB/s from a crossover to my older macbook pro w/ an upgraded ssd), so i don't know how good a speed you will get via a usb2 device (not better than 480Mb/s or 60MB/s since that's the usb2 spec limits).. unless that adapter is actually usb3.0.. something to consider, but i may be getting that same adapter because i am going to soon have a need for both my retina macbook's thunderbolt ports..

bottom line, if you can spare the thunderbolt port, don't mind the higher price, you'll get your money's worth on performance.. if you don't see a need of that performance (or have other external limitations like a 100meg only network), you can save some $ by getting a cheaper usb adapter

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Thanks, I really don't need USB adapter, I just want to keep it handy someday when I need to connect some LAN and my wireless adapter doesn't work. I had such issues like once in a while.. i won't use this adapter regularly.. hence hesistant to spend money for Apple product and just keep it away until I really have some use of it!

I got the 29 dollar gigabit thunderbolt adapter and the performance is really good (i've gotten over 750MB/s from a crossover to my older macbook pro w/ an upgraded ssd)...

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Be careful with the MB/s and Mb/s notations though. I think you mean 750 Mb/s in this case since 1 Gb/s is the max and 750 MB/s goes far beyond that

I've seen a very stable 100MB/s over my gigabit network between 2 notebooks both equipped with an ssd. I think the 100MB/s was actually limited by one of the ssd's (the ssd is an old model from 2009 and used a lot over that time). So in other words, I see the same kind of performance as you do. I did see that it went up to 940 Mb/s on my network with several iperf tests though.

Great performance but with a downside to it: you can't hook up an external monitor when you want to use gigabit ethernet Sadly there doesn't seem to be a usb3-gigabit ethernet card around with the same kind of performance as the thunderbolt adapter. If there was I'd definitely get one (I would leave the thunderbolt one at home and put the usb3 one in my bag). If the older and slower 100 Mbit is enough than the usb2-100Mbit adapter is a good one.

I really wish Apple had released the gigabit adapter as a USB 3 device instead of Thunderbolt.

Basically it forces you to decide on either gigabit ethernet or an external display with a Macbook Air. If you dock your laptop at your desk frequently, you probably want both. With a USB 3 gigabit adapter, you can just use one USB 3 port for gigabit, and plug a hub into the second port for the rest of your stuff.

I'm guessing Apple either wants to sell more Thunderbolt displays, or more likely, doesn't want to admit that USB 3.0 is just as useful as Thunderbolt.

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